At present, packaging boxes are commonly used in many occasions, such as food packaging, food taking away or medical material packaging, and so on. As the packing box may be used for packaging food such as rice and dishes, it should be well sealed to avoid accidental opening of the box cover, and prevent the spill of soup to a certain extent. However, the sealing performance of commonly used packing boxes cannot meet such requirements.
When opening the packaging box, the cover edge of the packaging box should be broken off with hands operating upward and arduously at first, and then the cover of the packaging box can be opened upward. During such process, as the structure of the packaging box is not conducive to be operated in such a way, the food or other contents in the packaging box may be spilled out.
In addition, as most of the packaging boxes are disposable, they often have a thin thickness. Accordingly, the thin surrounding walls cannot guarantee the strength, which results in deformation even damage of the packaging boxes when subjecting to the external force.